It's neat you've identified that bottleneck.  
dbench 192 also appears to trigger more swapin/swapout than 
usual with rmap based kernels about 12-15 minutes into the test;
and it remains unusually high for the duration of the run.  
(not a huge amount of swapping, but vmstat 60 shows double digit
numbers, rather than the more typical 0 with occasional single
digits "spikes").  dbench 64 doesn't trigger this behavior on 
my test box.
I want diversity in the workloads.  bonnie++ does a single
thread, and tiobench is doing 1, 2, 4, and 8 threads.  dbench
fits in well at the other end of the spectrum.
The newest bench added to the lineup is OSDB on postgresql.
If everything executes properly, 2.5.3-dj3 (which includes
radix-tree) will win the first timer award for OSDB. :)
-- Randy Hron- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/